A piezoelectric polymer material using a helical chiral polymer (for example, a polylactic acid polymer) having optical activity has been recently reported.
For example, a piezoelectric polymer material that exhibits a piezoelectric modulus of approximately 10 pC/N at room temperature through stretching of a molded article of polylactic acid is disclosed (see, for example, Japanese Patent Application Laid-Open (JP-A) No. H5-152638).
Moreover, in order to obtain highly oriented polylactic acid crystals, performing a special orientation process referred to as a forging method to achieve a piezoelectricity of approximately 18 pC/N has also been reported (see, for example, JP-A No. 2005-213376).
Meanwhile, a touch panel using a molecularly-oriented polylactic acid film and a touch type input device using this touch panel have been known (see, for example, WO 2010/143528).
In display devices such as a liquid crystal display device and an organic electroluminescence display device, a linear polarizer may be used (see, for example, JP-A Nos. 2006-268018, 2009-192611, and 2009-21408).